From:
Bruno Wolff III <bruno(at)wolff(dot)to>
To:
Mary Edie Meredith <maryedie(at)osdl(dot)org>
Cc:
Neil Conway <neilc(at)samurai(dot)com>,ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>,pgsql-patches(at)postgresql(dot)org
Subject:
Re: O_DIRECT for WAL writes
Date:
2005-06-03 19:24:51
Message-ID:
20050603192451.GA25970@wolff.to (view raw or flat )
Thread:
2005-05-26 08:04:01 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>
2005-05-26 14:15:07 from Neil Conway <neilc(at)samurai(dot)com>
2005-05-30 01:59:59 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>
2005-05-30 06:29:40 from Neil Conway <neilc(at)samurai(dot)com>
2005-05-30 06:52:09 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-05-30 07:04:41 from Neil Conway <neilc(at)samurai(dot)com>
2005-05-30 15:24:54 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-05-31 01:08:27 from Neil Conway <neilc(at)samurai(dot)com>
2005-05-30 08:04:48 from Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>
2005-06-02 00:08:14 from Mary Edie Meredith <maryedie(at)osdl(dot)org>
2005-06-02 01:39:25 from Neil Conway <neilc(at)samurai(dot)com>
2005-06-02 18:49:28 from Mary Edie Meredith <maryedie(at)osdl(dot)org>
2005-06-03 00:37:39 from Neil Conway <neilc(at)samurai(dot)com>
2005-06-03 16:43:13 from Mary Edie Meredith <maryedie(at)osdl(dot)org>
2005-06-03 19:24:51 from Bruno Wolff III <bruno(at)wolff(dot)to>
2005-06-04 16:52:55 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-06-21 05:43:57 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>
2005-06-21 13:23:39 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-22 19:25:00 from Greg Stark <gsstark(at)mit(dot)edu>
2005-06-22 19:50:04 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-23 17:16:01 from "Jim C(dot) Nasby" <decibel(at)decibel(dot)org>
2005-06-23 18:18:54 from Douglas McNaught <doug(at)mcnaught(dot)org>
2005-06-24 01:12:16 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-06-24 01:28:09 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-23 03:14:07 from Curt Sampson <cjs(at)cynic(dot)net>
2005-06-23 03:51:34 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-23 03:54:15 from Curt Sampson <cjs(at)cynic(dot)net>
2005-06-23 04:00:19 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-23 04:11:58 from Gavin Sherry <swm(at)linuxworld(dot)com(dot)au>
2005-06-23 04:25:34 from Gregory Maxwell <gmaxwell(at)gmail(dot)com>
2005-06-23 04:33:35 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-23 04:47:40 from Gavin Sherry <swm(at)linuxworld(dot)com(dot)au>
2005-06-23 05:04:59 from Curt Sampson <cjs(at)cynic(dot)net>
2005-06-24 01:54:57 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-06-24 04:16:44 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>
2005-06-24 13:37:23 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2005-06-24 15:19:14 from "Jim C(dot) Nasby" <decibel(at)decibel(dot)org>
2005-06-24 16:21:56 from Josh Berkus <josh(at)agliodbs(dot)com>
2005-07-07 04:58:31 from Mark Wong <markw(at)osdl(dot)org>
2005-07-14 17:30:39 from "Jeffrey W(dot) Baker" <jwbaker(at)acm(dot)org>
2005-06-28 07:21:10 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>
2005-07-02 20:16:47 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-07-23 17:32:30 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-07-27 05:50:11 from ITAGAKI Takahiro <itagaki(dot)takahiro(at)lab(dot)ntt(dot)co(dot)jp>
2005-07-27 13:38:52 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-08-06 21:04:19 from Mark Wong <markw(at)osdl(dot)org>
2005-08-09 22:21:00 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-07-29 03:23:55 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-08-11 20:31:44 from Mark Wong <markw(at)osdl(dot)org>
2005-08-11 20:36:10 from Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
2005-07-14 00:33:45 from "Jeffrey W(dot) Baker" <jwb(at)gghcwest(dot)com>
2005-07-14 19:34:32 from Greg Stark <gsstark(at)mit(dot)edu>
2005-07-14 19:44:18 from "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
2005-06-21 17:19:02 from Josh Berkus <josh(at)agliodbs(dot)com>
Lists:
pgsql-hackers pgsql-patches
On Fri, Jun 03, 2005 at 09:43:13 -0700,
Mary Edie Meredith <maryedie(at)osdl(dot)org> wrote:
>
> Looking at this from another angle, is there really any way that you can
> say a write is truly guaranteed in the event of a failure? I think in
> the end to be safe, you cannot. That's why (and I'm not telling you
> anything new) there is no substitute for backups and log archiving for
> databases. Databases must be able to recognize the last _good
> transaction logged and roll forward to that from the backup (including
> detecting partial writes to the log). I'm sure the PostgreSQL community
> has worked hard to do the equivalent of that within the PostgreSQL
> architecture.
Some assumptions are made about what order blocks are written to the disk.
If these assumptions are not true, you may not be able to recover using
the WAL log and have to resort to falling back to your last consistant
snapshot.
In response to
pgsql-hackers by date
Next :From: Bruno Wolff IIIDate: 2005-06-03 19:33:02Subject : Re: executing OS programs from pgPrevious :From : Tom LaneDate : 2005-06-03 19:16:29Subject : Re: executing OS programs from pg
pgsql-patches by date
Next :From: Simon RiggsDate: 2005-06-03 22:06:49Subject : WAL bypass for CTASPrevious :From : Mary Edie MeredithDate : 2005-06-03 16:43:13Subject : Re: O_DIRECT for WAL writes
